The numbers are obtained, though rounded, for x/32.5 s, where x is, and in order:
16
16.5
17
17.5
18
18.5
18.552625 (obtained by count pixels and some math to get a number, though it failed)
19

The problem is probably just because the graph is terrible for this kind of work, due to the fact that the graph came off some different problem that was intended for students to describe the graph, so the numbers aren't very well set.

These are the numbers I obtained off the few weeks of physics I had but any other input is fine.
Its also fine to give a guess off the top of your head, so i can try it, but please base it off something.